Re: unpack a single object

On Tue, Aug 11, 2009 at 1:49 PM, Bryan Donlan[off-list ref] wrote:

On Tue, Aug 11, 2009 at 4:48 PM, Bryan Donlan[off-list ref] wrote:

quoted

On Tue, Aug 11, 2009 at 4:15 PM, tarmigan[off-list ref] wrote:

quoted

I would rather not copy the whole good repo back to the one that ran
out of space because it's multiple gigs.  My plan is to just explode
the bad pack on of the corrupted repo, explode good pack and then,
copy the corrupted object back.  So my question is how do I tell which
pack contains that object?  (I would rather not explode all the packs
because of the repo size.)  Is there a way to extract a single object
from a pack without exploding the whole pack?

You should be able to just extract the single object in question:

goodrepo$ git cat-file commit 3d4c2b0225e7605a7e2a38ffc44dcb888589f4ce
 > ~/commit.dat
goodrepo$ cd ~/badrepo
badrepo$ git read-file -t commit ~/commit.dat
(should output 3d4c2b0225e7605a7e2a38ffc44dcb888589f4ce)

At this point your repo should be repaired.

Err, that should read git hash-object, not git read-file.

Thanks, and thanks to Junio who also responded with something similar
off-list.  I was vaguely familiar with cat-file and hash-object before
but didn't realize how they could be used to do what I wanted, so
thanks for the lesson.

As Junio suspected, I after the next fsck, I also had problems with
the tree associated with that commit and also the commits behind that
one.  Each fsck takes around 12 minutes, so replacing one commit at a
time seemed not very productive.  So now I am doing another svn clone
from scratch and letting it run for a few hours (it was a straight
mirror, so nothing is lost).  It seems somewhat wasteful, but I guess
better a few hours of cpu time than a few hours of my time.

Thanks,
Tarmigan